Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752289AbaAQO3K (ORCPT ); Fri, 17 Jan 2014 09:29:10 -0500 Received: from mail-ve0-f181.google.com ([209.85.128.181]:62298 "EHLO mail-ve0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752190AbaAQO3I convert rfc822-to-8bit (ORCPT ); Fri, 17 Jan 2014 09:29:08 -0500 MIME-Version: 1.0 In-Reply-To: <3781679.27UF2dWtKL@phil> References: <27256277.YJ687suYy5@phil> <1669323.jqjZBfkRx4@phil> <20140116124527.GD19578@e106331-lin.cambridge.arm.com> <3781679.27UF2dWtKL@phil> Date: Fri, 17 Jan 2014 08:29:07 -0600 Message-ID: Subject: Re: [PATCH] of: add function to count number of u32 elements in a property From: Rob Herring To: =?ISO-8859-1?Q?Heiko_St=FCbner?= Cc: Mark Rutland , "linux-arm-kernel@lists.infradead.org" , "arm@kernel.org" , "grant.likely@linaro.org" , "devicetree@vger.kernel.org" , Philipp Zabel , "linux-kernel@vger.kernel.org" , Greg Kroah-Hartman , Pawel Moll , Stephen Warren , Ian Campbell Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 16, 2014 at 12:04 PM, Heiko St?bner wrote: > The need to know the number of array elements in a property is > a common pattern. To prevent duplication of open-coded implementations > add a helper function that also centralises strict sanity checking > and DTB format details. > > Suggested-by: Mark Rutland > Signed-off-by: Heiko Stuebner > --- > Hi Mark, > did you mean it like this? I've tested it with the sram-reserve change and > it made the part of the determining the number elements a lot nicer :-) > > drivers/of/base.c | 32 ++++++++++++++++++++++++++++++++ > include/linux/of.h | 8 ++++++++ > 2 files changed, 40 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index f807d0e..0f40ea5 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -920,6 +920,38 @@ int of_property_read_u32_index(const struct device_node *np, > EXPORT_SYMBOL_GPL(of_property_read_u32_index); > > /** > + * of_property_count_u32_elems - Count the number of u32 values in a property > + * > + * @np: device node from which the property value is to be read. > + * @propname: name of the property to be searched. > + * > + * Search for a property in a device node and count the number of u32 elements > + * in it. Returns number of elements on sucess, -EINVAL if the property does > + * not exist or its length does not match a multiple of u32 and -ENODATA if the > + * property does not have a value. > + */ > +int of_property_count_u32_elems(const struct device_node *np, > + const char *propname) > +{ > + int elem_size = sizeof(u32); This should be a parameter, so functions for different sized properties can be a simple wrapper function. > + int len; > + struct property *prop = of_find_property(np, propname, &len); > + > + if (!prop) > + return -EINVAL; > + if (!prop->value) > + return -ENODATA; > + > + if (prop->length % elem_size != 0) { > + pr_err("size of %s is not a multiple of u32\n", propname); The node name would be useful here too. > + return -EINVAL; > + } > + > + return len / elem_size; > +} > +EXPORT_SYMBOL_GPL(of_property_count_u32_elems); > + > +/** > * of_property_read_u8_array - Find and read an array of u8 from a property. > * > * @np: device node from which the property value is to be read. > diff --git a/include/linux/of.h b/include/linux/of.h > index 276c546..5794942 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -253,6 +253,8 @@ extern struct property *of_find_property(const struct device_node *np, > extern int of_property_read_u32_index(const struct device_node *np, > const char *propname, > u32 index, u32 *out_value); > +extern int of_property_count_u32_elems(const struct device_node *np, > + const char *propname); > extern int of_property_read_u8_array(const struct device_node *np, > const char *propname, u8 *out_values, size_t sz); > extern int of_property_read_u16_array(const struct device_node *np, > @@ -432,6 +434,12 @@ static inline int of_property_read_u32_index(const struct device_node *np, > return -ENOSYS; > } > > +static inline int of_property_count_u32_elems(const struct device_node *np, > + const char *propname) > +{ > + return -ENOSYS; > +} > + > static inline int of_property_read_u8_array(const struct device_node *np, > const char *propname, u8 *out_values, size_t sz) > { > -- > 1.7.10.4 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/